A TWO-year field experiment was carried out at El-Serw Agricultural Research Station, during the 2018 and 2019 seasons to study the effect of intercropping cowpea (Vigna unguiculata L.) with three maize (Zea mays L) hybrids (SC 168, SC176 and TWC 321) and four N fertilization treatments (120kg N/fed as urea (100% N mineral), 50% N mineral + 50% N nano, 75% N mineral + 25% N nano and 3.0cm3 N nano/ L (100% N nano) on maize and cowpea productivity, land use efficiency and economic return. A split-plot design with three replicates was used. Results showed that maize hybrids had significant effect on yield and yield attributes of maize and cowpea in both seasons, with some exception. The S.C.168 hybrid gave the highest grain yield and its components, while intercropping cowpea with S.C.176 hybrid significantly increased yield and its attributes of cowpea in comparison with other hybrids. Applying 75% N mineral along with 25% N nano significantly increased growth, yield and yield components of maize and cowpea in both seasons. Significantly increase in yield and its attributes of maize and cowpea was realized by interaction between maize SC168 and 75% N mineral +25% N nano fertilization. Intercropping cowpea with maize SC168 that received 75% of the N mineral + 25% nano fertilizer recorded the highest LER 1.67 and 1.66, ATER 1.59 and 1.58, Aggressivity 0.28 and 0.23, gross return15865 and 15854 L.E./fed and net return 7983 and 7972L.E./fed in first and second seasons, respectively, as well as rationalizing the use of N mineral fertilizers.